Motor fuel composition



United States Patent 3,036,902 MQTGR FUEL COMPOSITION Martin Harmer, Chicago, 111., and Sherman R. ()blad, Munster, llnd., assignors to Standard Oil Company, Chicago, 111., a corporation of Indiana No Drawing. Filed Mar. 3, 1953, Ser. No. 718,490 6 Claims. (Cl. 44-56) This invention relates to motor fuel compositions and particularly to motor fuel compositions for spark-ignition internal combustion engines adapted to prevent engine stalling due to carburetor icing.

Engine stalling due to carburetor icing occurs most frequently under engine idling conditions and particularly under weather conditions of relatively high humidity and at a temperature below about 60 F. While this problem has been in existence for many years, it has of late become of increased importance because of recent engine design. Most post-war cars are provided with automatic chokes and provide no means for manual operation of the throttle so that operators of such cars are no longer able to regulate idle speeds during warmup periods to prevent stalling. Furthermore, the idle speed of automobiles equipped with automatic transmissions is rather critical during the warm-up period and the fastest idle rate which may be used is limited to avoid creeping. Another factor in carburetor icing is the high volatility of motor fuels now provided for present-day engines.

It has been established that the cause of engine stalling in cool hum-id weather is the formation of ice in the engine carburetor. On such cool moist days, the gasoline evaporated in the carburetor produces a sufiicient refrigerating elfect to condense and freeze the moisture present in the air entering the carburetor. Fuel vaporiza-.

tion in the fuel carburetor under such conditions can cause a temperature drop in the carburetor of up to 50 F, below that of the entering air; as a result, up to the time of complete engine and radiator Warm-up, this drop in temperature causes formation of ice crystals in the carburetor. The maximum refrigeration of the type referred to takes place under conditions of light load operation. As cooling of the carburetor parts takes place, ice begins to form as soon as these parts are refrigerated to a temperature below about 30 F., so that, when the throttle is closed to the idle position, the iCe forms, formed or forming in the carburetor, particularly that formed, on the throttle plate and the adjacent walls, closes the narrow air ports, thereby restricting the-normal flow of the air to the engine, causing repeated engine stalling. While an engine stalled, because of carburetor icing, can be readily started because the ice formed melts almost immediately due to residual heat from the exhaust manifold, it is highly desired to avoid any stalling due to carburetor icing because of the attendent inconvenience. For example, stalling due to carburetor icing of a car, equipped with automatic transmisison, frequently does not occur until the driver is ready to accelerate so that at this most inconvenient time it is necessary to shift the car to neutral, restart the engine and shift back into gear, all of which magnifies the inconvenience of frequent stalls.

It is an object of the present invention to provide a motor fuel fora spark-ignition internal combustion engine which will prevent carburetor icing. Another object of the invention is to provide gasoline for spark-ignition internal combustion engines which will prevent the accumulation of ice crystals on carburetor parts during idling speed and under conditions of light load operation. Still another object of the invention is to provide a hydrocarbon motor fuel composition for spark-ignition internal combustion engines which will prevent engine stalling 3,036,902 Patented May 29, 1962 2 due to carburetor icing. Other objects and advantages of the present invention will become apparent from the following description thereof.

In accordance with't-he present invention, the foregoing objects can be attained by incorporating in the motor fuel for spark-ignition combustion engines from about 0.005% to about 0.5 of a substituted imidazoline, more fully defined hereinafter, and in combination therewith from about 0.01% to about 3.0% of an alkanol having from 1 to about 4 carbon atoms, such as methanol, ethanol, isopropanol, propanol, l-butanol, 2-butanol, 2- methyl-Z-propanol and isobutanol. If desired, mixtures of such alkanols can be used.

The substituted imidzoline used in this invention can be represented by the following probable general structure:

N V RC6)(3)(5CH2 r de'cenyl imidazoline, l-aminoethyl-2undecyl imidazoline,

1-hydroxyethyl-Z-pentadecyl imidazoline, l-arninoethyl- 'Z-heptadecenyl imidazoline, l-aminoethyl-Z-heptadecyl imidazoline, 1-hydroxyethyl-2 heptadecyl imidazoline, 1-

(aminoethyl and the like.

Several commercial imidazoline compounds are available which can be used in the preparation of the above salts. Examples of such commercial products are Amine O, Amine 220, and Nalcamine G42, all of which contain R groups (above structure) of 17iearb'on'awms and a hydroxyl polar group (X in the above structure). Another commercial imidazoline is Nalcamine 6 39M which has the same R group but contains in its polar side group (X). f if 'fff The de-icer combination of the present inventioncan be used in any hydrocarbon motor fuel in the gasoline boiling range adapted for use in spark-ignition internal combustion engines. adapted to be used in the fall or spring (intermediate) and in the Winter months when stalling due to car-' buretor icing is most prevalent, have an ASTM initial boiling point of about '90-"80 F., a off distillation temperature of not more than about 365-356" F. respec-' tively and an end point of not more than about 415 F.

Typical gasoline inspections are illustrated by the following:

Intermediate Winter The hydrocarbon motor fuel can contain any of the commonly used additives such as lead alkyl anti-knock agents, e.g. tetraethyl lead, lead scavenging agents, dyes,

ethylamino-) 2-heptadecenyl imidazoline,

Such hydrocarbon motor fuels 3 gum inhibitors, oxidation inhibitors, corrosion inhibitors, spark plug-fouling inhibitors, etc.

The etfectiveness of de-icers in preventing engine stalls is determined in a single cylinder Lauson H-2 engine equipped with a down-draft carburetor operated under the following conditions: Air from a CFR ice tower, and having a dry bulb temperature of 37-40 F. and a wet bulb temperature of 3437 F. is fed to the carburetor of the engine operating on a test cycle of five minutes at full throttle, 1800 r.p.m., and five minutes at idle, 1800 r.p.m. This test cycle is repeated until the engine stalls.

Using, as the base fuel, a winter grade leaded gasoline containing a commercial antioxidant, and a spark-plug fouling inhibitor, and having the following ASTM distillation characteristics:

F. Initial boiling point 80 recovery 106 50% recovery 191 90% recovery 1 302 End point t 376 The following samples were subjected to the above deicer test:

Sample 1Controlno deicer Sample 2Control+0.15% 1 methanol Sample 3Control+0.0l% l-hydroxyethyl 2 heptadecenyl imidazoline Sample 4No. 3+0.15% methanol Sample 5--Control+0.005% l-hydroxyethyl 2 heptadecenyl irnidazoline Sample 6NO. 5 +0.15 methanol Sample 7--Control+0.50% isopropanol+0.25% methanol Sample 8-Control+0.02% glycerol mono-oleate Sample 9-Control+0.025% dimethyl formamide 1 Volume percent. The results obtained are tabulated in Table I:

of the combination of a substituted imidazoline and an alkanol (Samples 4 and 6) as a de-icer over each component alone (Samples 2, 3 and 5) and other known deicers (Samples 7, 8, and 9).

Percentages given herein and in the appended claims are volume percentages unless otherwise stated.

While the present invention has been described with reference to preferred embodiments thereof, the invention is not be be considered as limited thereto, but includes within its scope such modifications and variations as come within the spirit of the appended claims.

We claim: 1. A hydrocarbon motor fuel composition for sparkignition internal combustion engines to render said engines non-stalling due to carburetor icing comprising a major amount of a hydrocarbon distillate in the gasoline distillation range, and containing in combination there with in suflicient amounts to inhibit carburetor icing under icing conditions (1) from about 0.005% to about 0.05% of a hydroxyl-substituted imidazoline having the structural formula in which R is a hydrocarbon radical having from about 10 to about 24 carbon atoms selected from the group consisting of an alkyl radical, an alkenyl radical and an alkadienyl radical, and (2) from about 0.01% to about 3.0% of an alkanol containing from 1 to about 4 carbon atoms.

2. A hydrocarbon motor fuel composition as described in claim 1 in which R is an alkenyl radical of from about 10 to about 24 carbon atoms.

3. A hydrocarbon motor fuel composition as described in claim 1 in which R is an alkyl radical of from about 10 to about 24 carbon atoms.

4. A hydrocarbon motor fuel composition as described in claim 1 in which the alkanol is methanol.

5. A hydrocarbon motor fuel composition for sparkignition internal combustion engines to render said engines non-stalling due to carburetor icing comprising a major amount of a hydrocarbon distillate in the gasoline distillation range, and in combination therewith in sufficient amounts to inhibit carburetor icing under icing conditions 1) from about 0.005% to about 0.05% to 1- hydroxyethyl-2-heptadecenyl irnidazoline and (2) from about 0.01% to about 3.0% methanol.

6. The method of preventing the stalling of sparkignition internal combustion engines due to carburetor icing in moist cool temperature conditions which comprises burning in said engine a hydrocarbon fuel composition comprising a major amount of a hydrocarbon distillate in the gasoline distillation range, and containing in combination therewith (1) from about 0.005% to about 0.05% of a hydroxyl-substituted imidazoline having the structural formula CHzCHaOH in which R is a hydrocarbon radical having from about 10 to about 24 carbon atoms selected from the group consisting of an alkyl radical, an alkenyl radical and an alkadienyl radical, and (2) from about 0.01% to about 3.0% of an alkanol containing from 1 to about 4 carbon atoms.

References Cited in the file of this patent UNITED STATES PATENTS 2,553,183 Caron et al May 15, 1951 2,599,338 Lifson et al June 3, 1952 2,622,018 White et al. Dec. 16, 1952 2,915,376 Raifsnider Dec. 1, 1959 OTHER REFERENCES Petroleum Refining With Chemicals, by Kalichevsky and Kolbe, Elsevier Publ. Co., 1956, page 480.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,036,902 May 29, 1962 Martin Hamer et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Co1un1n 2, line 7, for 0.5915" read 0.05% line 14, for "lmldzollne" read imidazoline column 4, line 35, for "to", second occurrence, read 0f Signed and sealed this 4th day of September 1962.

(SEAL) Attest:

DAVID L. LADD Commissioner of Patents ERNEST W. SWIDER Atteeting Officer 

1. A HYDROCARBON MOTOR FUEL COMPOSITION FOR SPARKIGNITION INTERNAL COMBUSTION ENGINES TO RENDER SAID ENGINES NON-STALLING DUE TO CARBURETOR ICING COMPRISING A MAJOR AMOUNT OF A HYDROCARBON DISTILLATE IN THE GASOLINE DISTIALLATION RANGE, AND CONTAINING IN COMBINATION THERE WITH IN SUFFICIENT AMOUNTS TO INHIBIT CARBURETOR ICING UNDER ICING CONDITIONS (1) FROM ABOUYT 0.005% TO ABOUT 0.05% OF A HYDROXYL-SUBSTITUTED IMIDAZOLINE HAVING THE STRUCTURAL FORMULA 